The endocannabinoid system as a target for modelling psychosis.

Model psychosis refers to experimentally induced symptoms resembling schizophrenia, such as withdrawal from reality, perceptual disturbances, thought disorders, delusions, and sometimes hallucinations. These altered states of consciousness help researchers understand aspects of schizophrenia. The endocannabinoid system has become a focus of investigation due to its discovery and epidemiological evidence linking cannabis use to the onset and course of schizophrenia. Most studies examine cannabis and cannabinoid effects not directly related to psychosis. This review summarizes studies relevant to or designed as model psychosis experiments, examining their contribution to understanding endocannabinoid functioning in psychosis and schizophrenia, and outlines future research directions and cross-links to other modeling approaches.

Study at a glance

Abstract

Model psychosis is characterised by experimentally induced symptoms of withdrawal from reality, frequently accompanied by perceptual disturbances, thought disorders, delusional ideas and sometimes by hallucinations. These "altered states of consciousness" provide a long-standing and valid approach to enhance our understanding of certain aspects of schizophrenia. Targeting the endocannabinoid system to investigate its involvement in the pathophysiology of schizophrenia became increasingly relevant with the discovery of this system and amounting epidemiological evidence for a deleterious influence of cannabis use on both manifestation and course of the disease. The majority of studies in the field are targeted to investigate drug effect of cannabis and cannabinoids not immediately related to psychosis. In this review, we summarise studies relevant for or designed as model psychosis experiments. Based on the data available, we examine the contribution of these studies to an improved neurobiological assessment of endocannabinoid functioning in psychosis and schizophrenia. An outline for future studies in the field and cross-links to other approaches to model psychosis is provided.